Hillock-free multilayer metal lines for high performance thin film structures.

摘要

A multilayered thin film structure, for example for metal lines in integrated circuits, comprising alternating layers of a base metal (54) such as aluminum and a barrier metal (56) such as a refractory metal or alloy. The base metal, in any given layer, is deposited to a thickness less than its critical thickness - a thickness beyond which hillocks are more likely to form for a given temperature. Between each such layer of base metal, a layer of barrier metal is interposed. The intervening layer of barrier metal acts to suppress the formation of hillocks in the base metal.